Ram Jet w/ O2 sensor ?s

[RamJetFSJ]

I know you guys arent Chevy pros, but I figured there may be a few EFI pros hanging around.

As most of you know, I have the RamJet 350 in my wag. It used the MEFI computer, and is a open loop style controller. Meaning it has the fuel curves programmed in, and does not have a O2 sensor to continually adjust the air fuel mixture (which is said to be the only major flaw of the Ram Jet 350).

Just found out Arizona Speed & Marine sells a conversion kit, to use a closed loop setup, with a O2 sensor, for the Ram Jet. Includes everything, including a reprogrammed computer. Supposed to give you better performance, milage, and lower emissions.

Obviously Im not too worried about milage, and emissions arent a big deal, but I would like to be able to go as far on a tank of gas as possible, and more performance is always better, especially if its part throttle (ive got plenty of full throttle performance).

http://www.azspeed-marine.com/newitems-1.html

So what do you think? Would it be worth it? It runs $450. What kind of improvements should I expect? I emailed AS&M, but havnt gotten a response back yet...

Thanks Guys!

[ September 20, 2002, 11:28 AM: Message edited by: RamJetFSJ ]

[RamJetFSJ]

btt

[Josh D]

My opinion would be for the closed loop system. You never have to worry about tuning for altitude, barometric pressure, etc. Start it up and drive!

[mdill]

It will take a lot of gas to pay for itself, but it should help keep
the RamJet running longer, as they had to setup the origional
more on the rich side to compensate for manufacturing and wear
and tear, don't know if you will feel any seat of the pants
performance, but if $ are not a great object go for it !

Mike D.

[trssho]

The main advantage is that you have have optimum air/fuel ratio also known as stoichiometric. This does not mean you will have optimum performance. I would prefer the closed loop, but for optimum power, you would be best served in open loop.

[RamJetFSJ]

So a closed loop wont get me much performance, if any, but will make daily driving a little better, slightly better milage, will run better at alititude, and make the motor last longer. What about COOLING, will being at the optimum air fuel ratio keep the motor running cooler? (not the water cooler, but less heat created by the motor?)

Thanks for all the info guys!!! I still dont know if I should by it or not though... smile.gif

Im hoping TPIGuy chimes in with his opinion...

Ben

[Josh D]

Let me start by saying I'm no FI expert, but from what I understand, open loop is more for one dimensional vehicles, i.e. race car, where certain conditions never really change, or can be manually tuned to changes with an eprom burn or control box. A closed loop system still requires an eprom burned to "tune" to a specific engine and setup (can be tuned to run rich or lean/economy or performance) but utilizes things like O2 sensors in the exhaust to change air/fuel ratio as ambient conditions change (i.e. altitude, load, temperature, etc), therefore suited better for multi-dimensional vehicles such as a daily driver/tow/4X4 type rig.